This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The overall purpose of this study is to better understand how insulin influences brain function in aging and Alzheimer's Disease. Functional MRI will be used to study how and where insulin works in the brains of both normal people and those with very mild Alzheimer's disease.